Summary N-Methylated amides (N,4-dimethylbenzamide and N-methylcyclohexanecarboxamide) were systematically subjected to chemical transformations, namely, N-tosylation followed by nucleophilic substitution. The amide function was converted to the corresponding carboxylic acid, esters, amides, aldehyde, and ketone upon treatment with hydroxide, alkoxide, amine, diisobutylaluminium hydride and Grignard reagent, respectively. In these transformations, N-methyl-N-tosylcarboxamides behave like a Weinreb amide. Similarly, N-methyl-5-phenylisoxazole-3-carboxamide was converted into 3-functionalized isoxazole derivatives. Since the amide was prepared by the cycloaddition reaction of ethynylbenzene and N-methylcarbamoylnitrile oxide, the nitrile oxide served as the equivalent of the nitrile oxides bearing a variety of functional groups such as carboxy, alkoxycarbonyl, carbamoyl, acyl and formyl moieties.

Development of Variously Functionalized Nitrile Oxides. -N-methylated amides (I) are converted to versatile carbonyl functions via N-tosylation followed by nucleophilic substitution. The term nitrile oxide is used because it is a part of isoxazole that is easily prepared by cycloaddition of ethynylbenzene and N-methylcarbamoylnitrile oxide. -(ASAHARA*, H.; ARIKIYO, K.; NISHIWAKI, N.; Beilstein J. Org. Chem. 11 (2015) 1241-1245, http://dx.doi.org/10.3762/bjoc.11.138 ; Sch. Environ. Sci. Eng., Kochi Univ. Technol., Kami, Kochi 782, Japan; Eng.) -F. Mueller 41-035